Device for boring noncircular holes



Oct. 8, 1929. 1. c. JENNINGS 1,730,429

DEVICE FOR BORING NONCIRCULAR HOLES Original Filed Aug. 29, 1924 2SheetsSheet l c, T I a I 2z FD 21* Q a 11 .14" 1820 if l g 6 15 w H MW 1v'f/lll .Il

IN m/v 'nm -JF/{Z 6.7 1202 W A TTORNE Y-S Oct. 8, 1929. I. c. JENNINGSDEVICE FOR BORING NONCIRGULAR HOLES Original Filed Aug. 29, 1924 2Sheets-Sheet Patented Get. 8, 1929 Davies non nonrne NONQIR-CULAR noLnsApplication filed August 29, 1924, Serial N0. 734t,'924. Renewed March11, 1929.

The object of this invention is to provide an attachment for machinetools so that the same can be employed for boring non-circular holes.

My attachment has been particularly designed for use on a boringmill oran engine lathe and will be particularly shown and described as appliedto a boring mill.

To this end, the cross feed for the cross slide mounted on the crossrail of the boring mill to which the attachment is to be applied isdisconnected, so that the cross slide can move freely on the rail, andan arm or attachment is secured to the cross slide and an annular cam isfitted on the work to engage said arm. This engagement preferably ismade through a roller journalled in a bearing piece adjustably carriedby the arm, which roller engages the outer periphery of the cam.

In using this arrangement, the work is first fastened on the table orface plate and is faced 0E and bored so that the cam can be securedthereon. The cam preferably has a depending fiange which canfitaccurately into the hole bored in the work. Then the attachment isbrought into operation, whereby as the work is rotated the cross slidewill be moved back and forth on the cross rail under the influence ofthe cam and an irregular or non-circular hole determined by the shape ofthe cam will be accurately bored in the work.

The attachment is advantageous in operation as the connection betweenthe cam to the operating tool is very solid and strong, as the armengages the outer periphery of the cam and the tool engages the work atthe same side of the center.

The invention is illustrated in the accompanying two sheets of drawingsforming part of this application for patent, in which-- Fig. 1 is afront elevation partly in section of a boring mill with my attachmentapplied thereto;

Fig. 2 is a plan view thereof;

Fig. 3 is a side elevation on an enlarged scale of the attachment; and

Fig. A is a cross-section of the parts illustrated in Fig. 3.-

Referring to the drawings, and in detail, A

designates the revolving table or base plate of a boring mill, 13-13 thetwo uprights, C the cross rail or carriage, and D one of the crossslides, which carries the ram E in which the cutting or boring tool F issecured. These parts are of the ordinary construction and require nodetailed description. 1

In using my invention, the feed for the right hand cross slide 1) isdisconnected so that the same can movev freely on the cross ran. bracket10 which can be secured by suitable bolts to the side of. said crossslide D. A slide 11 is dove-tailedinto said arm or bracket 10 so that itcan be moved relatively thereto, a nut 12, screw13 and hand wheel 14being provided for this purpose. A roller 15 is mounted on a pin 16secured in said slide, a ball bearing being preferably used between theroller and pin. w

The work W is secured on .the table in any desired way. Thetopoftlie'work is first faced off andthen a rib or fiange17 on the topthereof isbored out accurately. A cam piece is then secured on top ofthe work. I

This cam .piece preferably consists of a'circular piece 18, which has adepending flange 19, which is of a size tofit accurately into thecircular hole bored in the rib 17, and a cam shaped piece 21 fastened byscrews 22 to the circular piece 18. The circular piece 18 is secured tothe work by bolts 20. This cam construction is adapted so that the camsurface 21 can be easily machined and can be replaced as desired. Afterthe cam piece is secured to the work, the toolis adjusted to engage theinside periphery of the work and it is fed The attachment consists of anarm or down therein by the usual feed employed in the cross slide forthat purpose.

By the arrangement described, the cross slide willmove back and forth onthe cross rail under-the infiuenceof the cam and the tool will bore anirregular shaped or noncircular hole conforming to the contour of thecam 21. By adjusting the wheel-14E the cut of'the tool can be regulated.

A heavy spring 23 is arranged betweenthe cross slide D and a stationarypart, so that the cross slidewill be pulled to the left to keep theroller in engagement with the cam.

As the engagement of the cam with the roller determines the cuttingposition of the tool, it will be seen that a very smooth and accuratehole can be bored by the means described, as spring of the parts ispractically eliminated as the strain due to the cut is takenvby the armor bracket 10 which is se-v cured directly to the cross slide 1).

As the engagement of the roller 15 with the cam section 21 and theengagement of the tool F with the inside of the work W take place at thesame side of the center of the work as shown in the plan, Fig. 2, itwill be seen that the push of the cam is transmitted to force thecutting tool into the Work through very few parts and that an accurateirregu-= lar shaped hole will be bored in the work as spring of theparts is practically eliminated.

The details and arrangements herein shown and described may be greatlyvaried by a skilled mechanic without departing from the scope of theinvention as expressed in the claims. V 7

Having thus fully described my invention, what I claim and desire tosecure by Letters Patent is 1. The combination in a machine tool of arevolving face plate, a cross rail or carriage, a cross slide fittedloosely thereon, a ram or tool holder fitted in the cross slide, a camadapted or arranged 'to be connected or mounted on the work,and anattachment on the cross slide engaging the outer periphery.

of the cam at the same side of the center that the tool engages theinside of the work.

2. 'The combination in a machine tool, of a revolving face plate, across rail or carriage,

a cross slide fitted loosely thereon, a rain or tool holder fitted inthe cross slide, an annular cam adapted or arranged to be connected ormounted 011 the work and an attachment secured to the cross slide andengaging the outer periphery of the cam at the same side of the centerthat the tool engages the inside of the work.

3. The combination in a machine tool, of a revolving face plate, a crossrail or carriage, a cross slide fitted loosely thereon, a ram or toolholder fitted in the cross slide, and an attachment consisting of abracket secured to the cross slide, a slide adjustably carried thereby,and a cam adapted or arranged to be connected or mounted on the work andengaging the slide.

4. The combination in a machine tool, of a revolving faceplate, a crossrail or carriage, a cross slide fitted loosely thereon, a ram or toolholder fitted in the cross slide, and an attachment consisting of abracket secured to the cross slide, a slide adjustably carried by saidbracket carrying a roll, and a cam adapted or arranged to be connectedor mounted on the work and engaging the roll.

5. The combination in. a machine tool, of a revolving face plate, across rail or carriage,

IRVING 0. JENNINGS.

